The upcoming S1 and S2 Android tablets aren't the only new devices that Sony is working on. Apparently during yesterday's presentation, there were a couple of Vaio systems that slipped under the radar, perhaps because the company provided very little details about them. But here's what know: it includes a new ultra-thin notebook and a "Freestyle Hybrid PC" that switches between tablet laptop modes.

The latter sports a similar form factor to Samsung's Sliding PC 7 Series and the ASUS Eee Pad Slider. It's believed to be the rumored Sony Vaio Slider that surfaced a couple of months ago, which will reportedly feature a 9.4-inch display, an Intel Pine Trail class Atom processor and Windows 7 as the operating system of choice. There's no word on pricing or availability yet but going by previous rumors it could start shipping this fall starting at $800.

As for the "Ultra Mobile PC" it is said to pack a 13.3-inch display and Atom processor into a slim body sporting the Vaio's traditional sharp lines and monochrome color scheme – but that's about it as far as details go. Akihabara News notes both systems are "scheduled to come anytime soon" so we expect to hear more in the next few weeks.